Partly due to lack of access to effective pain medications, many people with chronic pain and fibromyalgia turn to over-the-counter herbal treatments such as kratom. While this plant definitely has some pain-relieving potential, there are concerning safety and side effects that need to be considered. This article reviews our current scientific understanding of this intriguing plant.

Botany:Kratom (Mitragyna speciosa)is a tree native to Thailand and swampy areas of Southeast Asia. It is in the plant family Rubiaceae, which also includes the coffee plant.

Traditional Use:The chopped fresh or dried leaves of the tree are chewed or made into tea by local farmers and manual laborers to combat fatigue and improve work productivity. In addition, kratom preparations have traditionally been used to treat fever and pain, and more recently to treat opioid dependence. Despite its widespread use, Thailand banned it in 1943 due to its abuse potential, as did Malaysia in 2004.

Status in the US: More than two million Americans consume kratom every year, where it is sold over the counter as a supplement. This means it doesn’t have to pass through federally mandated testing or clinical trials and is not regulated for purity or potency. It has been banned in six U.S. states: Alabama, Arkansas, Indiana, Tennessee, Vermont, and Wisconsin. In 2016, the DEA initiated a formal process to make kratom a Schedule I drug, one with “no currently accepted medical use” such as heroin. However, the DEA backed off after a public outcry and regulation still remains in the hands of the FDA.

Medicinal Actions:· Kratom’s effects on the body are dosage dependent. In lower doses it acts as a stimulant, resembling the effect of drugs such as cocaine or amphetamines. In larger doses it acts as a pain reliever and can have sedative effects that resemble drugs such as opiates.· The primary active ingredients of kratom are mitragynine and 7-hydroxymitragynine, which bind to some of the same receptors in the brain as opioids. They have analgesic effects comparable to morphine, but cause less constipation, respiratory depression, and tolerance compared to opioids such as morphine. They also have some anti-inflammatory effects. · Chronic kratom users can develop a tolerance and experience symptoms of withdrawal. The symptoms of withdrawal are almost identical to opioid withdrawal (insomnia, anxiety, diarrhea, runny eyes and nose) and are treated in a similar manner. · Pharmaceutical companies tried mitragynine on its own as a treatment, but it caused side effects of nausea and vomiting that halted further development efforts. In studies no compound isolated from kratom exhibits as much benefits as the whole leaves. This is the classic synergistic effect so often seen with herbal medicines. · Kratom pharmacology is complex, containing at least 40 different known phytochemicals, and is thought to have actions on many other receptors in addition to the opioid receptors, including dopamine, serotonin, GABA, and norepinephrine receptors. However, scientists aren’t exactly sure how kratom exerts its stimulant effects.

Side EffectsThere are reports of kratom causing elevated blood pressure, toxicity to kidneys and heart, impaired cognition, psychosis, and life-threatening liver failure. Long-term kratom use has been associated with drug dependency, development of withdrawal symptoms, and cravings. Long-term addicts can develop skin pigmentation on their cheeks, due to the capacity of mitragynine to increase the production of melanocytes-stimulating substance.

We are also now learning that kratom has some of the same hormonal side effects as opioids. One of my male patients reported erectile dysfunction due to kratom, and a medical journal published a case of kratom causing increased prolactin and low testosterone levels.

Safety issuesAlthough kratom has less respiratory suppression effects compared to opioids such as morphine, it still can be a deadly substance when mixed with other compounds. There are case reports of overdose deaths due to mixtures of kratom with over-the-counter cold medications, sleep medications, or benzodiazepines (such as Valium). At present, kratom constituents are not detected by conventional drug screening tests, making it hard for health care providers to screen for abuse.

The other major safety issue is that kratom is sold only on the unregulated supplement market, meaning it can be adulterated with other medications. In Sweden, kratom laced with the active ingredient of tramadol was associated with several overdose deaths. Unregulated supplements can also be contaminated with bacteria or toxins, as occurred in a multistate Salmonella outbreak that prompted the Centers for Disease Control and Prevention to issue a warning about kratom to consumers.

A recent scientific article on kratom recommended “testing and labeling requirements should be implemented to inform consumers of alkaloid contents and to protect consumers from adulterated products.”

ConclusionEveryone in chronic pain would agree that we absolutely need more treatment options, not less. In particular, we must find safer treatments that give the benefits of opioids with fewer side effects and less addiction risk. To me, kratom has some exciting therapeutic potential on that front, but is not ready yet for medicinal use due to some unanswered questions about safety and lack of reliable access to high quality, standardized products.